Cutting floating single-walled carbon nanotubes with a ‘CO₂ blade’

Uniform ultra-short (<100 nm) single-walled carbon nanotubes (SWCNTs) with properties of rich chemistry, high dispersity and easy manipulation, are of great importance for constructing novel nano-structures and highly integrated miniature devices. Herein, we report a recent breakthrough in cutting long SWCNTs into uniform ultra-short segments in gas-phase using CO₂ as a ‘blade.’ SWCNTs synthesized by an aerosol reactor are directly introduced into a second reactor for gaseous cutting. The quality and the number concentration of shortened SWCNTs are enhanced after the gas-phase cutting process. Moreover, the growth and cutting of SWCNTs are accomplished in a continuous gas-phase process, thus allows direct dry deposition of ultra-short SWCNTs as individual macromolecules or thin films onto various substrates for multiple applications.